Height distributions of U.S. children: associations with race, poverty status and parental size.

The stature of children, relative to that of a reference population, is often used as a measure of the nutritional status of a population. But while undernourished children are often small in stature, all small-statured children cannot be assumed to be undernourished as a wide range of hereditary, socioeconomic and health factors also influence growth processes. The distribution of heights of 3850 "healthy" U.S. children 1-11 years of age who participated in the first National Health and Nutrition Examination Survey, a probability sample of the U.S. population, have been examined in relation to age- and sex-specific reference medians, and in relation to race, family income, and height of their parents. The distribution of heights of black children was shifted to the right (i.e., taller) of that of white children (Index of Dissimilarity = 7.9%). The distribution of heights of children of above poverty level income families was shifted to the right of that of children of below poverty level income families (Index of Dissimilarity = 8.4%). In both races, and with family incomes both above and below the poverty income level, the distribution of heights of children of tall parents was shifted to the right of that of children of short parents (Index of Dissimilarity = 20.25%). We concluded that parental stature, economic conditions and race must be considered in interpreting the growth of children in all societies, and before concluding that nutritional factors are the major determinants of short stature.